Awe-inspiring design of Warragamba Dam

Sydney Design Week focus on Warragamba Dam

The award-winning architectural design of Warragamba Dam Visitor Centre, ground-breaking feats of engineering design of Australia’s biggest domestic water supply dam, and the awe-inspiring natural design of its catchment were showcased during Powerhouse Sydney Design Week 2023.

WaterNSW joined with more than 60 events from 15-24 September as part of the Powerhouse Museum’s celebration of the critical research, industries, infrastructure and technologies that underpin design practice in Sydney.

The range of Sydney Design Week events was expanded this year to explore the complex and interconnected social and natural ecologies in which contemporary design operates.

WaterNSW was delighted Warragamba Dam was included as one of the standout new sites to explore the social, environmental and ethical issues facing designers, researchers and architects.

Tours started in the Visitor Centre’s Burragorang Room with its spectacular views over the lake and dam wall.

Traditional owner Kazan Brown welcomed visitors on to Gundungurra Country and shared the creation story of how the deep gorges of the Burragorang Valley were gouged in a cross-country battle between two Dreamtime ancestors Mirrigan, a quoll like hunter and fisherman, and the rainbow eel Gurungatch. At the end of the battle, Gurangatch had carved out the Wollondilly and Coxs rivers, including the deep waterholes where he rested and tried to hide from Mirragan.

The Visitor Centre’s architect, Annabel Lahz, Director, lahznimmo architects, then spoke about her vision and design for the building and grounds that won architecture and landscape architecture awards following its completion in 2009.

Brian Mayhew, General Manager Regional Operations Sydney, spoke about engineering design of the dam wall, constructed from 1948 to 1960 by 1,800 workers from 25 different nationalities. Three million tonnes of concrete went into the 142-metre high dam wall that is holding back four Sydney Harbours volume of water.

Mary Knowles, Catchment Area Manager, completed the presentation by analysing the natural design of Warragamba Dam’s 9,050 square kilometre catchment. She emphasised how the natural environment and built environment are inextricably linked in managing the health of Greater Sydney’s drinking water catchment.

Lake Burragorang
Lake Burragorang holds four times the volume of Sydney Harbour, and collects water from a 9,050 square kilometre catchment stretching from Lithgow to Goulburn.
Design week speakers
Speakers at the WaterNSW event during Powerhouse Sydney Design Week were (from left) Brian Mayhew, Annabel Lahz, Mary Knowles and Kazan Brown.

Catchment influences design – and design influences health of catchment

“When you are designing something you need to understand where does this fit in the landscape? What impact will the landscape have on me? What impact will I have on the landscape?” Mary said.

“The answers to these questions are pretty obvious when you are building a dam like Warragamba – you need to know how big to build the dam, how much water will flow down the rivers to the dam, how much water do I need it to hold, how much do I need it to release during floods?

“But these are the same questions we should be asking for everything from urban planning and rural farming practice to recreational opportunities and natural area management.

“If we plan and design urban landscapes and developments well, we can reduce and sometimes improve the health of the natural environment. If urban development is done poorly, the health of our catchment declines.

“Water sensitive urban design is the integration of water management into planning, design and construction of the built environment. For example, ensuring stormwater from the built environment is filtered and slowed down before it enters our streams to ensure that nutrient and sediment are retained higher in the landscape and not within our waterways.

“In the rural landscape, we design practices that reduce impacts on our streams and waterways. Examples include adjusting grazing intensity to maintain groundcover, and excluding stock from riparian areas which creates a buffer so you don’t lose nutrients into the creeks and rivers,” Mary said.

Mary Knowles
Mary Knowles, WaterNSW Catchment Area Manager, describing how this drainage line was fenced and planted with trees, over time becoming a best practice example of catchment land management.
Fenced dam in paddock
Excluding stock from riparian areas protects water quality by creating a buffer so landholders don’t lose nutrients into creeks and rivers.

Tall narrow dam holding a vast amount of water

Brian Mayhew, General Manager Regional Operations Sydney, spoke about how the Warragamba River offered two important advantages as a site for a major dam: a large catchment area, and a river flowing through a narrow gorge.

“This meant a tall and narrow dam capable of holding a vast amount of water could be built,” Brian said. “The designers spent four years on site investigations including drilling bore samples to understand the geology of potential dam sites, and settled on this site.”

Brian described the huge forces in play holding back more than 2,000 gigalitres of water: “The pressure behind the dam is in effect trying to push the wall down the valley, at the same time as water in the rock under the dam is trying to push it up. The designers took these water pressure and uplift pressures into account in designing this concrete gravity dam.”

The dam was built in a series of large interlocking concrete blocks. Overhead cableways lifted 18 tonne buckets to carry concrete across the Warragamba Gorge to build each block. Ice was mixed with the concrete to control heat generation and prevent cracks.

Two temporary (coffer) dams and a tunnel were built to divert the Warragamba River and keep the site dry so excavation for the dam could start. Concrete was mixed on site using 305,000 tonnes of cement and 2.5 million tonnes of sand and gravel. Sand and gravel were transported from McCann's Island in the Nepean River via an aerial ropeway.

concret blocks
Warragamba Dam was built in a series of large interlocking concrete blocks. Overhead cableways lifted 18 tonne buckets to carry concrete across the Warragamba Gorge to build each block.
Brian Mayhew
Brian Mayhew, WaterNSW General Manager Regional Operations Sydney, describing the huge forces in play holding back more than 2,000 gigalitres of water at Warragamba Dam.
Visitor Centre

Warragamba Dam’s award-winning Visitor Centre sits high on a bluff overlooking the dam wall and lake, with a series of public viewing platforms cascading down the rock shelves.

Free entry to our Visitor Centre and picnic grounds

Warragamba Dam is located 65 kilometres west of the Sydney CBD, on the lands of the Gundungurra Nation.

Visitors can enjoy the landscaped picnic grounds of Haviland Park, panoramic views of the dam wall and Lake Burragorang from viewing platforms, and the ‘Water for Life’ exhibition at our Visitor Centre.

Warragamba Dam grounds are open 8am to 5pm daily (10am to 7pm on weekends and public holidays during Daylight Savings).

The Visitor Centre is open daily from 10am-4pm. Entry is free to the grounds and Visitor Centre. WaterNSW looks forward to welcoming you soon.

Published date: 25 September 2023

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